Fresh Gas Flow Rate and Perioperative Lung Aeration Assessed by Lung Ultrasound in Septoplasty

NCT07758517 | Completed

• 2 other identifiers: FSM-LUS-20232023/129
• Study Type: observational
• Target: 2
• Locations: 1 country
• Sites: 1

Brief Summary

This prospective, single-center observational cohort study evaluated the association between fresh gas flow rate during inhalational anesthesia and perioperative changes in lung aeration in adults undergoing elective surgery for nasal septal deviation. Participants were classified into two cohorts according to the fresh gas flow rate used during routine anesthesia care: 1 L/min or 3 L/min. The flow rate was selected independently by the attending anesthesiologist as part of routine clinical practice and was not assigned by the research protocol. Lung aeration was assessed using the modified lung ultrasound score before anesthesia, after tracheal intubation, before extubation, 15 minutes after admission to the post-anesthesia care unit, and before discharge from the post-anesthesia care unit. Perioperative oxygenation, hemodynamic variables, respiratory mechanics, and early postoperative recovery findings were also recorded.

Conditions

Atelectasis; Nasal Septal Deviation

Keywords

Fresh gas flow rate; Low-flow anesthesia; Inhalational anesthesia; Lung ultrasound score; Lung ultrasound; Perioperative atelectasis; Pulmonary aeration; Septoplasty; Desflurane; Post-anesthesia care unit

Outcome Measures

Primary Outcomes (1)

• Perioperative Change in Modified Lung Ultrasound Score

  Lung aeration was assessed in 12 thoracic regions, six regions in each hemithorax. Each region was scored from 0 to 3: 0 indicated normal aeration, 1 mild loss of aeration, 2 moderate loss of aeration, and 3 severe loss of aeration or consolidation. Regional scores were summed to obtain a total modified lung ultrasound score ranging from 0 to 36. Higher scores indicated greater loss of lung aeration. Changes in the total score across the perioperative time points were compared between the 1 L/min and 3 L/min fresh gas flow cohorts.

  Preoperative baseline; after tracheal intubation; before extubation; 15 minutes after PACU admission; and approximately 30 minutes after PACU admission or before PACU discharge

Secondary Outcomes (6)

• Perioperative Peripheral Oxygen Saturation

  Preoperative baseline; after tracheal intubation; before extubation; 15 minutes after PACU admission; and approximately 30 minutes after PACU admission or before PACU discharge

• Intraoperative Dynamic Lung Compliance

  Approximately 5 minutes after tracheal intubation and immediately before extubation

• Intraoperative Peak Airway Pressure

  Approximately 5 minutes after tracheal intubation and immediately before extubation

• Intraoperative Airway Resistance

  Approximately 5 minutes after tracheal intubation and immediately before extubation

• Postoperative Pain Intensity

  At 15 minutes and approximately 30 minutes after admission to the PACU

Study Arms (2)

1 L/min Fresh Gas Flow Cohort

Participants who received inhalational general anesthesia with a fresh gas flow rate of 1 L/min as part of routine anesthetic care. The fresh gas flow rate was selected independently by the attending anesthesiologist and was not assigned by the research protocol. Perioperative lung aeration was evaluated using the modified lung ultrasound score.

Other: Fresh Gas Flow Rate of 1 L/min

3 L/min Fresh Gas Flow Cohort

Participants who received inhalational general anesthesia with a fresh gas flow rate of 3 L/min as part of routine anesthetic care. The fresh gas flow rate was selected independently by the attending anesthesiologist and was not assigned by the research protocol. Perioperative lung aeration was evaluated using the modified lung ultrasound score.

Other: Fresh Gas Flow Rate of 3 L/min

Interventions

Fresh Gas Flow Rate of 1 L/min OTHER

During routine inhalational general anesthesia, a fresh gas flow rate of 1 L/min was used. The flow rate was selected independently by the attending anesthesiologist according to routine clinical practice and was not assigned or modified by the research protocol. This exposure was evaluated in relation to perioperative changes in the modified lung ultrasound score.

1 L/min Fresh Gas Flow Cohort

Fresh Gas Flow Rate of 3 L/min OTHER

During routine inhalational general anesthesia, a fresh gas flow rate of 3 L/min was used. The flow rate was selected independently by the attending anesthesiologist according to routine clinical practice and was not assigned or modified by the research protocol. This exposure was evaluated in relation to perioperative changes in the modified lung ultrasound score.

3 L/min Fresh Gas Flow Cohort

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

The study population consisted of adults aged 18 to 65 years with American Society of Anesthesiologists physical status I or II who underwent elective septoplasty for nasal septal deviation under general anesthesia at Fatih Sultan Mehmet Training and Research Hospital. Eligible consenting participants were observed prospectively, and their perioperative clinical and lung ultrasound data were recorded. Fresh gas flow rates were selected by the attending anesthesiologist as part of routine clinical care.

You may qualify if:

• Adults aged 18 to 65 years
• Scheduled to undergo elective septoplasty for nasal septal deviation under general anesthesia
• American Society of Anesthesiologists physical status I or II
• Body mass index of 35 kg/m² or less
• Provided written informed consent to participate

You may not qualify if:

• Acute respiratory tract infection within the preceding 15 days
• Chronic pulmonary disease
• Malignancy
• Significant hepatic, renal, or cardiac disease
• Limited ability to cooperate with the study assessments
• Cerebrovascular or neuromuscular disease
• Previous thoracic surgery
• Chest wall deformity
• Emergency surgery
• History of clinically relevant allergy

Sponsors & Collaborators

• Fatih Sultan Mehmet Training and Research Hospital: lead

Study Sites (1)

Istanbul Provincial Health Directorate Fatih Sultan Mehmet Training and Research Hospital

Istanbul, 34000, Turkey (Türkiye)

Location

MeSH Terms

Conditions

Pulmonary Atelectasis

Condition Hierarchy (Ancestors)

Lung Diseases; Respiratory Tract Diseases

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor of Anesthesiology and Reanimation

Study Record Dates

• First Submitted: August 6, 2026
• First Posted: August 11, 2026
• Study Start: January 10, 2024
• Primary Completion: January 10, 2025
• Study Completion: April 15, 2025
• Last Updated: August 11, 2026

Record last verified: 2026-08

Locations

TU (1)